Windows has encountered an error...HL2 mods

[GrimNecroWizard]

I've had HL2 for more than a year and it's never done this before. It seems to happen a few times a day now. When playing Battlegrounds or Hidden Source or something, it'll randomly crash and say Windows has encountered an error and you get the box to send and you just hit cancel or whatever. It's never done this before, what do I need to do to get it to stop? Sometimes when I just hit escape it'll crash like that.

Pentium 4 3.2ghz
1gig ddr2sdram
x300se (Which has worked fine for a year)

[CappyCobra]

PC is most likely overheating. Open her up and give it a good dusting. Check the fans and make sure they are running ok. Leave the case open and run a house fan at it to see if the issue persists

[GrimNecroWizard]

I think that's what it might be, the back of my PC is full of dust. I'll get on that. Thanks